[The application of "expiration holding" in measuring end expiration pulmonary artery wedge pressure in patients undergoing mechanical ventilation].

OBJECTIVE: To find an accurate and convenient method of measuring end expiratory pulmonary artery wedge pressure (eePAWP) by "expiration holding" function of ventilator and "pulmonary artery wedge pressure (PAWP) Review" software of monitor. METHODS: Twelve patients with introduction of pulmonary artery catheter and undergoing mechanical ventilation were selected. Fifty measurements were randomly selected for the comparison of the differences between automatic measurement and expiration holding method in each patient. There were 21 cases underwent single positive pressure ventilation and 29 cases with positive pressure ventilation mixed with spontaneous breathing. All measurements were first divided into <8 mm Hg (1 mm Hg=0.133 kPa) or ≥8 mm Hg groups according to respiratory variability (RV). They were then divided into automatic measurement group and expiration holding group according to PAWP measurement, and the difference in the results between two groups were recorded. RESULTS: In 21 cases with single positive pressure ventilation, in 12 cases PAWP (mm Hg) of automatic measurement group was higher than that of expiration holding group (12-16 vs. 9-14) when RVP<8 mm Hg, but the difference between two groups was not obvious, and measurements were similar occasionally. In automatic measurement group PAWP (mm Hg) was higher than that of expiration holding group (13-20 vs. 9-15) in 9 cases when RV≥8 mm Hg, the difference was obvious. Neither RVP<8 mm Hg nor RV≥8 mm Hg, the statistical difference was significant (all P<0.01). In 29 cases, when positive pressure ventilation was mixed with spontaneous breathing, RVP<8 mm Hg (n=13), RV≥8 mm Hg (n=16), most of the results in automatic measurement group were higher than those of expiration holding group (11-18 vs. 10-17), and only 4 of them were lower than expiration holding group (11-20 vs. 14-23). There was no statistically significant difference between two groups (all P>0.05). CONCLUSION: Expiration holding measurement is a better method that can identify the eePAWP, and it reflects the true hemodynamic status more accurately and quickly whether positive pressure ventilation only or positive pressure ventilation mixed with spontaneous breathing is given.

[The impact of early restrictive positive fluid balance strategy on the prognosis of patients with severe trauma].

OBJECTIVE: To observe the impact of early restrictive positive fluid balance strategy on the prognosis of patients with trauma. METHODS: A prospective controlled study was conducted. The patients with severe post-trauma capillary leak syndrome (PTCLS) admitted to department of critical care medicine of the Fifth Center Hospital in Tianjin were considered as study object. Fluid treatment was adjusted according to intra-thoracic blood volume index (ITBVI), mean arterial pressure (MAP), cardiac index (CI) and oxygen saturation of central vein (ScvO2) at leakage stage of PTCLS. Patients were divided into two groups according to different fluid therapy volume, restrictive positive fluid balance group (restrictive group) and non-restrictive positive fluid balance group (non-restrictive group), 30 patients were enrolled into each group. The fluid balance volume and index of prognosis between two groups were analyzed within 7 days of treatment. RESULTS: During the leakage stage of PTCLS, compared with non-restrictive group, fluid positive volume of the restrictive group were decreased at 1-6 days of the treatment (1 day: 5968.8±1818.0 ml/d vs. 7109.7±2186.41 ml/d, 2 days: 3653.7±1525.1 ml/d vs. 6080.3±1538.8 ml/d, 3 days: 1953.6±621.3 ml/d vs. 3223.3±875.1 ml/d, 4 days: -2808.7±888.0 ml/d vs. -4169.9±1302.5 ml/d, 5 days: -5969.1±1470.8 ml/d vs. -6896.5±1619.4 ml/d, 6 days: -1938.1±746.0 ml/d vs. -4964.0±1389.6 ml/d, P<0.05 or P<0.01), ITBVI and extravascular lung water index (EVLWI) were decreased at 2 days and 3 days of the treatment (ITBVI 2 days: 689.2±60.6 ml/m(2) vs. 807.7±67.8 ml/m(2), 3 days: 729.6±43.3 ml/m(2) vs. 825.5±71.5 ml/m(2); EVLWI 2 days: 6.9±2.0 ml/kg vs. 8.3±2.1 ml/kg, 3 days: 7.6±2.0 ml/kg vs. 8.9±1.9 ml/kg, P<0.05 or P<0.01). Compared with non-restrictive group, the occurrence of respiratory dysfunction (46.7% vs. 76.7%), gastrointestinal dysfunction (33.3% vs. 60.0%) and the occurrence of intracranial hypertension (26.7% vs. 56.7%) at 7 days of treatment in restrictive group were decreased (all P<0.05), the time of mechanical ventilation (3.6±1.1 days vs. 5.1±1.5 days) and intensive care unit (ICU) stay time (5.5±1.5 days vs. 7.0±1.9 days) were shortened (both P<0.01). There were no differences in the occurrence of dysfunction of cardiovascular, blood coagulation, hepatic and renal function, the percentage of patients receiving renal-replacement therapy and the number of days with dialysis, as well as the mortality during the first 28 days between two groups (all P>0.05). CONCLUSION: Using restrictive positive fluid balance strategy in the leakage stage of PTCLS, fluid positive balance volume, occurrence of dysfunction of some organs, mechanical ventilation and ICU stay time can be decreased.